Kinetic Characteristics of Nitriding of Zr–1 Nb Alloy

摘要

We study the kinetic characteristics of nitriding of thin-sheet (~ 1 mm) samples of Zr–1% Nb alloy treated in a nitrogen atmosphere (documentclass[12pt]{minimal} usepackage{amsmath} usepackage{wasysym} usepackage{amsfonts} usepackage{amssymb} usepackage{amsbsy} usepackage{mathrsfs} usepackage{upgreek} setlength{oddsidemargin}{-69pt} begin{document}$$ {P}_{{textrm{N}}_2}={10}^5textrm{Pa} $$end{document}) in broad temperature (T = 550; 650; 750; 850 and 950°С) and time (τ = 1; 5 and 10 h) ranges. It is shown that the process of nitriding of the analyzed alloy obeys a law close to a parabolic dependence (n ≈ 2). It is discovered that the activation energy of nitriding of the alloy within the temperature range 550–950°C is equal to 131.8 kJ/mole. The microstructure of the subsurface layer of the alloy after nitriding is analyzed. The distribution of the surface microhardness of Zr–1% Nb alloy is determined. The diagrams of intensity of the phase reflexes of α-Zr and ZrN on the surface of alloy after treatment in a nitrogen atmosphere are constructed.